Waterproof, breathable fabric for outdoor athletic apparel

ABSTRACT

A layered fabric for constructing action sportswear. The fabric generally comprises the following three layers: (1) a shell fabric comprised of a blend of polypropylene filaments and LYCRA® brand spandex fibers, (2) a waterproof membrane laminated to the back of the shell fabric, and (3) a mesh lining, attached to the back of the membrane. The fabric has the qualities of being waterproof, breathable, and elastic and possess a number of other qualities which are highly desirable in action sportswear.

FIELD OF THE INVENTION

The present invention relates generally to fabrics for constructingathletic apparel, and more particularly to fabrics that are waterproof,breathable and elastic, and which possess a number of othercharacteristics that are highly advantageous in action sportswear.

BACKGROUND OF THE INVENTION

Outdoor sports which involve a great deal of aerobic activity on thepart of the athlete, such as surfing, bicycling, skiing and the likerequire apparel having certain desired characteristics, as follows:

1. Low Thermal Conductivity

An important feature of surfing apparel, for example, is its ability toinsulate the wearer from the cold water. This is especially important assurfing is increasingly becoming a year-round sport and surfers seek topractice their sport in the winter months. Likewise, in the sport ofbicycling, the wind chill factor creates a particular need forinsulating garments, especially when riding down-hill at high speeds.

2. Abrasion Resistance and High Tensile Strength

The ability to resist abrading is an essential quality of any garmentworn by body surfers and bicyclists.

Body surfers, who ride waves without the benefit of a surfboard,frequently slide against the surface of the rocky and sandy ocean flooras the wave approaches the beach. This can cause enormous frictionbetween the surfer's body and the ocean floor. Accordingly, any garmentworn must be able to resist tearing so as to prevent abrasions and burnsto the wearer.

Clothing worn by bicyclists must likewise be strong and abrasionresistant as serious abrasions can result from falls against pavementwhen riding at high speeds.

3. Vapor Permeable

The sports of surfing, bicycling and running are highly aerobic innature and therefore cause significant perspiration on the part of theathlete. Accordingly, the clothing worn by these athletes must allow theperspiration of the wearer to evaporate in the form of water vapor whichcan readily pass through the garment (i.e. "breathe") .

4. Lightweight

In bicycling, running and surfing, especially during competition, lightweight is a critical characteristic of garments demanded by mostathletes. Variations of only a few ounces can often have an impact onathletic performance. Moreover, with surfwear, it is obviouslypreferable that the fabric worn be lighter than water.

5. Colorfast and Sunfast

The current market for athletic wear demands clothing which is not onlyfunctional but also fashionable. This is particularly true of beachwear,where trends and fads routinely dictate seasonal color schemes. Often,these colors are bright, distinctive, and even fluorescent. Hence, thefabric must retain its color after exposure to sun, perspiration, orwashing.

6. Stain and Odor Resistant

Stains and odors are obvious problems with outdoor athletic apparel.With regard to surf-wear in particular, there is a risk of stains fromalgae and similar marine organisms as well as oil and other pollutantspresent at many beaches. These organisms and pollutants, together withperspiration, can also cause odors.

7. Hold, Mildew and Bacteria Resistant

Water provides a habitat for many different microorganisms. Among thebacteria most commonly found in natural waters are sulfur bacteria, ironbacteria, free-living spriral forms, certain pigmented and nonpigmentedspecies, and some spore-formers. Similarly, fungi such as molds andmildew, merely require abundant moisture, a supply of organic matter,and a supply of oxygen for growth.

Hence, apparel worn for surfing and other outdoor sports should ideallybe resistant to bacteria and fungi.

8. Waterproof

Many surfers, especially those who practice their sport in cold water,prefer to wear waterproof apparel commonly referred to as "dry suits."Such apparel not only allows the addition of insulating layers, but alsopermits athletes with cuts and abrasions to surf while protecting theirwounds from the salt water. Dry suits are also more comfortable to manysurfers. Similarly, the quality of being waterproof is desirable forapparel worn by skiers.

Moreover, many bicyclists and runners prefer waterproof apparel, as theyfrequently encounter unanticipated precipitation while riding orrunning.

9. Wind Resistance

Wind resistance is an important quality for bicyclists due to the windchill factor inherent in riding downhill at high speeds as with surferswho frequently ride waves at speeds exceeding 20 mph. Even faster speedsare achieved during downhill skiing.

10. Elasticity

Elasticity is the extent of elongation of the fabric upon application oftension, and the recovery to original length and shape when the tensionis released. This is an essential feature of any garments worn bybicyclists and surfers who prefer garments which are snug but flexibleand comfortable. In fact, the current market for surfwear, bicyclewearand skiwear is dominated by apparel which is "form fitting" and"skin-tight" rather than that which is loose and baggy.

While most prior art fabrics possess some of the above characteristicsand a few possess the majority thereof, no known fabric possesses all ofthese characteristics. For example, a fabric which has been found topossess the first seven of the ten characteristics listed above may beconstructed from a fine denier filament polypropylene yarn sold underthe trademark TELAR® by Filament Fiber Technology of Bay Head, N.J.TELAR® is a filament comprised primarily of polypropylene, aparafin-based synthetic fiber classed under the generic name of olefin.According to Fairchild's Dictionary of Textiles, Sixth Edition, knownuses of polypropylene fibers include upholstery fabrics, sweaters,swimwear, women's hosiery, and rugs.

However, it has heretofore been unknown to employ polypropylenefilaments in garments which are waterproof, wind resistant, and elastic,which, as stated, are desirable for the sports of surfing and the like.

There also exists in the art several fabrics which have the combinedcharacteristics of being waterproof, breathable, and stretchable. Forexample, U.S. Pat. No. 4,443,511 to Worden et al. discloses a waterproofand breathable elastomeric polytetrafluoroethylene (PTFE) layeredarticle. Other examples of elastic fabrics which are waterproof andbreathable are disclosed in U.S. Pat. No. 4,972,522 to Rantenberg, andU.S. Pat. No. 5,036,551 to Dailey et al. However, these fabric are alsounsuitable for constructing garments for outdoor sports because theylack other essential qualities such as abrasion resistance, low thermalconductivity, lightweight, colorfastness, and resistance to stain, odor,and bacteria.

It should be apparent, therefore, that there still exists a need in theart for a fabric for constructing outdoor athletic apparel whichpossesses all of the desired characteristics discussed above.

SUMMARY OF THE INVENTION

The present invention, therefore, is directed to a layered fabric whichis insulating, abrasion resistant, breathable, lightweight, colorfast,sunfast, and resistant to stains, odors, mold and mildew, while at thesame time being both waterproof, wind resistant and elastic. Theinvention generally comprises the following three layers: (1) a shellfabric comprised of a blend of polypropylene filaments and LYCRA® brandspandex fibers, (2) a waterproof membrane laminated to the back of theshell fabric, and (3) a mesh lining, attached to the back of themembrane. More particularly, the polypropylene filaments which comprisethe first layer are preferably continuous and, ideally, of a fine deniersuch as 100 or less.

A principal advantage of the fabric of the present invention is that itis waterproof but has the ability to allow moisture vapor to passtherethrough.

Another advantage of the fabric of the present invention is that itprovides thermal insulation and wind resistance.

Yet another advantage of the fabric of the present invention is that itis stretchable and elastic.

A further advantage of the fabric of the present invention is that ithas a high tensile strength and is highly resistant to abrasion.

Another advantage of the fabric of the present invention is that it islightweight.

Still another advantage of the fabric of the present invention is thatit is colorfast and sunfast.

A further advantage of the fabric of the present invention is that it isresistant to stains and odors.

Another advantage of the fabric of the present invention is that it isresistant to mold, mildew, and bacteria.

With the foregoing and other objects, advantages and features of theinvention that will become hereinafter apparent, the nature of theinvention may be more clearly understood by reference to the followingdetailed description of the invention, the appended claims and to theattached drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic view of the three-layered fabric of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The fabric of the present invention is illustrated schematically in FIG.1, and referred to generally by the numeral 10. Fabric 10 preferablycomprises an outer shell fabric 12 made from a blend of continuouspolypropylene filaments and another fiber having elastomeric propertiessuch as spandex; a waterproof, breathable, stretchable membrane 14laminated to the back of shell fabric 12; and a mesh lining 16 attachedto the back of membrane 14.

More particularly, shell fabric 12 is comprised primarily of continuouspolypropylene filaments. The polypropylene filaments employed in theshell fabric are preferably of a fine size, no greater than about 150denier and ideally no greater than 100 denier. ("Denier" is equivalentnumerically to the number of grams per 9000 meters; hence, the higherthe denier, the heavier the filament.) Polypropylene filaments of asuitable denier are known to be produced by Filament Fiber Technology,Inc. of Bay Head, N.J. (FFT) and sold by FFT under the Trademark TELAR®.(References below to "polypropylene" should be construed to meancontinuous polypropylene filaments, preferably of a fine denier.)

While polypropylene filaments have good resiliency (i.e. recoverabilityto original size and shape after being crushed or wrinkled), they do nothave outstanding elasticity (i.e. ability to elongate upon applicationof tension and recover to original length and shape when tension isreleased). The quality of elasticity is not particularly important inmany of the articles in which polypropylene is commonly used, such asupholstery and carpets. It is, however, a very important quality ingarments worn by surfers, runners, and bicyclists.

In order to increase the elasticity of the shell fabric 12, anelastomeric fiber is blended with the polypropylene filaments. Theelastomeric fiber employed is preferably LYCRA® brand spandex fiberproduced by the E. I. du Pont de Nemours Co. Such a fiber has remarkableelasticity, high strength, abrasion resistance and a flex life greaterthan conventional elastic threads. A preferred composition of shellfabric 12 is 85% polypropylene and 15% spandex.

An important characteristic that is not inherent in shell fabric 12, butone that is critical for garments worn by surfers, is waterproofness. Inorder to provide fabric 10 with this quality, a waterproof membrane 14is laminated to the back of shell fabric 12.

Membrane 14 may be any waterproof but breathable material, which iseither non-porous or porous. A preferred material is Sympatex®, aproprietary material of AKZO Fibers Inc. of Newburyport, Mass. Sympatexis a non-porous laminate film which may be bonded with adhesive or byheat fusion to shell fabric 12. The "dot method" may be employed toadhere the film to fabric 12. Sympatex® has high abrasion resistance andflex tolerance, thereby allowing fabric 10 to stay waterproof even afterextensive use over many years. Sympatex® is described more particularlyin U.S. Pat. No. 4,493,870 (expressly incorporated herein by reference)as a waterproof film material of a copolyether ester consisting of aplurality of recurrent intralinear long-chain ester units andshort-chain ester units which are randomly joined head-to-tail throughester bonds. The long chain ester units correspond to the formula:##STR1## and the short-chain ester units correspond to the formula:##STR2## where G is a divalent radical remaining after removal ofterminal hydroxyl groups from at least one long-chain glycol having amolecular weight in the range of 800 to 6000 and an atomic ratio ofcarbon to oxygen in the range of 2.0 to 4.3 at least 70% by weight ofthe long chain glycol having a carbon to oxygen ratio in the range of2.0 to 2.4, R is a divalent radical remaining after removal of carboxylgroups from at least one carboxylic acid having a molecular weight lessthan 300, and D is a divalent radical remaining after removal ofhydroxyl groups from at least one diol having a molecular weight lessthan 250, at least 80 mole % of the dicarboxylic acid used consisting ofterephthalic acid or the ester forming equivalents thereof and at least80 mole % of the low molecular weight diol consisting of 1,4-butanediolor the ester forming equivalents thereof, the sum of the molepercentages of the dicarboxylic acid which is not terephthalic acid orthe ester forming equivalents thereof and of the low molecular weightdiol which is not 1,4-butanediol of the ester forming equivalentsthereof is not higher than 20 and the short-chain ester units form50-75% by weight of the copolyether ester.

In lieu of Sympatex®, other waterproof, breathable laminates may beemployed to form membrane 14. For example, a porous membrane of expandedpolytetrafluoroethylene (PTFE) may be employed as membrane 14. PTFE ismade by following the techniques of U.S. Pat. No. 3,953,566. Suchmembranes and modified forms thereof are commercially available underthe registered trademark GORE-TEX®, sold by W. L. Gore & Associates,Inc. These expanded, porous PTFE membranes satisfy the requirements ofbeing waterproof while also being permeable to the flow of water vapor.The expanded porous PFTE membranes are inherently hydrophobic andcontain very small pores that resist the entry of liquid water even atsubstantial pressures or when rubbed or flexed, but readily allow theflow of gases including water vapor.

In use, membrane 14 functions to keep the wearer dry by preventing theflow of water (designated "W" in FIG. 1) through the fabric 10 whileallowing perspiration in the form of vapor (designated "V" in FIG. 1) toevaporate from the wearer to the outside of the fabric 10.

In order to protect the membrane 14 and to increase the comfort to thewearer, a lining 16 is attached to membrane 14 opposite the side onwhich the membrane is laminated to shell fabric 12. The lining 16 ispreferably constructed of a tricot mesh material. Tricot is a warp knitfabric made with two sets of threads.

Fabric 10 of the present invention comprises the following characterics,all of which are particularly important with regard to surfing andbiking apparel:

MOVEMENT OF MOISTURE

Fabric 10 has the ability to move moisture in the vapor phase from oneside of the fabric to the other where it can evaporate into theatmosphere. Hence, it does not seal moisture in against the skin as mostother synthetic fabrics do. This also allows the fabric to dry fasterand prevents the cold, clammy feeling to the wearer from having watertrapped against his or her skin which often occurs with non-breathablefabrics.

With reference to FIG. 1, water vapor, designated by the arrows V, isshown moving from the inside 18 of the fabric to the outside 20 of thefabric where it evaporates into the atmosphere. In particular, the vapormay easily pass through lining 16, which, as a mesh, is inherentlybreathable. Membrane 14, is preferably comprised of Sympatex® which hasa vapor transmission rate of at least 1000 g/m² day. Likewise, shellfabric 12 is constructed substantially of polypropylene fibers which arealso inherently breathable.

LOW THERMAL CONDUCTIVITY

The lower the thermal conductivity of a material, the slower heat istransported through it, (in the case of fibers, along their lengths andacross their diameters). Polypropylene, the principle component of shellfabric 12, has the lowest thermal conductivity of all common apparelfibers as shown by the following chart:

    ______________________________________                                        Fiber:        Thermal Conductivity                                            ______________________________________                                        Polypropylene 6                                                               PVC           6.4                                                             silk          7                                                               polyester     7.3                                                             wool          8                                                               acrylic       8                                                               nylon         10                                                              viscose       11                                                              cotton        17.5                                                            ______________________________________                                    

ABRASION RESISTANCE

The abrasion resistance of fabric 10 which, as stated is particularlyimportant for biking and surfing apparel, primarily depends upon theabrasion resistance properties of shell fabric 12 since this comprisesthe outer layer. Polypropylene is ranked with nylon in its excellentability to resist abrasions.

    ______________________________________                                        Fiber:            Abrasion Resistance:                                        ______________________________________                                        polypropylene     excellent                                                   nylon                                                                         cotton            good                                                        spandex                                                                       polyester                                                                     flax              fair                                                        wool                                                                          silk                                                                          rayon                                                                         acrylic                                                                       acetate           poor                                                        ______________________________________                                    

STRENGTH

Shell fabric 12 is very strong because polypropylene, with a strengthrange of 4.8-7.0 grams per denier, is one of the strongest fibers.Nylon, which is widely regarded as a strong fiber, has a strength rangeof 2.5-7.3 grams per denier. Moreover, nylon loses 15% of its strengthwhen wet, which polypropylene does not.

Membrane 14 and lining 16 also contribute to the overall strength offabric 10.

    ______________________________________                                        ABSORBENCY                                                                    Fiber:         Moisture regain:                                               ______________________________________                                        polypropylene  0.05                                                           polyester      0.4                                                            acrylic        1.6                                                            nylon          4.5                                                            acetate        6.5                                                            cotton         8.0                                                            silk           11.0                                                           rayon          13.0                                                           wool           16.0                                                           ______________________________________                                    

As the above chart illustrates, polypropylene is among the leastabsorbent of the textile fibers. Since little moisture is absorbed intothe fiber shafts, drying time is kept to a minimum. Hence, while theshell fabric 12 is not itself waterproof, because water is not absorbedinto the polypropylene fiber shafts, the wearer can easily shake off theexcess water.

Membrane 14 is, of course, waterproof; the absorbency of lining 16 isirrelevant since it is protected from water by the membrane 14.

WEIGHT

Fabric 10 is particularly light-weight, which, as stated, is aparticular advantage in garments worn by athletes since the weight of agarments can greatly impact athletic performance.

One study examined the effect of increased weight on bicyclingperformance and produced the following data:

    ______________________________________                                        bicycling 100 yards from a                                                    standing start:                                                               + 2 lbs.              1.3      ft. lag                                        + 6 lbs               4.1      ft. lag                                        bicycling on a 10 degree slope (1 mi.                                         ascent, 1 mi. descent)                                                        + 2 lbs               97       ft. lag                                        + 6 lbs               289      ft. lag                                        ______________________________________                                    

(Bicycling Magazine, April, 1988.)

Specific Gravity

Polypropylene, which largely comprises shell fabric 12, is one of thelightest of all apparel fibers, as seen from the following table:

    ______________________________________                                               polypropylene                                                                           0.91                                                                nylon     1.14                                                                acrylic   1.17                                                                wool      1.32                                                                silk      1.34                                                                polyester 1.38                                                                PVC       1.38                                                                cotton    1.50                                                                rayon     1.52                                                         ______________________________________                                    

On a scale with water set at 1.0, polypropylene has a specific gravityof 0.91, the only fiber listed weighing less than water. Hence, garmentsconstructed of polypropylene can provide bulk and warmth without beingheavy. Referring to the table above, cotton is 60% heavier thanpolypropylene, wool 40% heavier, polyester 52% heavier.

Additionally, polypropylene is perhaps the only fiber that does not addto the wearer's weight when wet. This is a particular advantage withrespect to apparel worn by surfers.

Membrane 14 and mesh lining 16 are similarly light in weight.

STAIN RESISTANCE

Polypropylene is an inert polymer, and is therefore fabric 10 does notstain readily.

COLORFASTNESS

Because it is made substantially from polypropylene, shell fabric 12,the outermost layer of fabric 10, is extremely resistant to fading andbleeding. In fact, dark and light colored garments comprised of thisfabric can be safely washed together. Garments dyed with a given pigmentbatch match other garments dyed with the same pigment years earlier.

STATIC RESISTANCE

Static resistance is an important property affecting the comfort offabric 10. Especially in the winter, static makes garments unpleasant toput on and uncomfortable to wear. As the following chart makes clear,polypropylene is among the better fibers with respect to staticresistance.

    ______________________________________                                        Fiber:             Static Resistance:                                         ______________________________________                                        glass              excellent                                                  spandex                                                                       polypropylene      good                                                       cotton                                                                        flax                                                                          rayon                                                                         wool               fair                                                       silk                                                                          acetate                                                                       acrylic            poor                                                       nylon                                                                         polyester          very poor                                                  ______________________________________                                    

PILLING RESISTANCE

Pilling is a process of forming small tangles of fibers when the surfaceof a material is rubbed either against itself or a foreign substance.The following chart ranks a given fiber's ability to resist pilling.

    ______________________________________                                        Fiber:                Ranking:                                                ______________________________________                                        glass                 excellent                                               spandex                                                                       polypropylene         good                                                    flax                                                                          silk                                                                          cotton                                                                        acetate                                                                       rayon                                                                         wool                  fair                                                    acrylic                                                                       nylon                 poor                                                    polyester             very poor                                               ______________________________________                                    

Pilling resistance, like static resistance, is a property that affects agarment's appearance and comfort. Since polypropylene is the onlyman-made non-cellulosic fiber that scores high in both static resistanceand pilling resistance, the fabric 10 is highly advantageous in thisregard.

CHEMICAL INERTNESS

The fabric 10 is highly resistant to chemical attack becausepolypropylene is the most chemically resistant of all synthetic fibers.It is very resistant to acids (at room temperature), alkalies (at roomtemperature), alcoholic solvents, silicon oils, and greases.

Chlorine falls among the chemicals to which polypropylene isresistent--giving the fabric 10 tremendous potential for pool andwater-related uses such as bathing suits.

MOLD, MILDEW, AND BACTERIA RESISTANCE

The fabric 10 is not affected by mold, mildew or bacteria becausepolypropylene cannot support these organisms in normal use, and is neverdamaged by them. It holds no moisture and is not a substance with whichthey can support their "nutritional" needs.

ELASTICITY

Fabric 10 is rendered elastic by virtue of the LYCRA® or similarelastomeric fiber which is blended with the polypropylene to constructouter shell fabric 12. Shell fabric 12 is elastic in all four directionsbecause of the spandex fibers included in the blend. The remaininglayers, namely, membrane 14 and lining 16, while not inherently elastic,are sufficiently stretchable so as not to inhibit the elasticity of thecomposite fabric 10. The arrows of FIG. 1 illustrate the elasticity orstretchability of the respective layers.

The elasticity of fabric 10 is an important quality in apparel worn bybicyclists and surfers which prefer garments which are tight, ratherthan baggy, while at the same time allowing the wear to move freely.

WATERPROOFNESS

As stated, a critical characteristic of fabric 10 is its waterproofness.Accordingly, fabric 10 may be used advantageously to construct "drysuits" worn by surfers.

The waterproofness of fabric 10 is due to membrane 14. As illustrated inFIG. 1, water, W, which may for example be rain or ocean water,penetrates shell fabric 12 but is repelled by membrane 14.

Fabric 10 will also be wind resistant due to the wind resistantcharacteristics of membrane 14.

In use, fabric 10 will undergo the known cut, make, and trim (CMT)processes to construct apparel specifically designed to be worn duringsurfing, biking, and other outdoor action sports. Apparel so constructedwill have the qualities of being insulating, abrasion resistant,breathable, lightweight, colorfast, sunfast, and resistant to stains,odors, mold and mildew while at the same time being both waterproof,wind resistant and elastic.

Although certain presently preferred embodiments of the invention havebeen described herein, it will be apparent to those skilled in the artto which the invention pertains that variations and modifications of thedescribed embodiment may be made without departing from the spirit andscope of the invention. Accordingly, it is intended that the inventionbe limited only to the extent required by the appended claims and theapplicable rules of law.

What is claimed is:
 1. A layered fabric for use in constructing sportsapparel comprising:a first fabric layer comprised of a blend ofpolypropylene filaments and an elastomeric fiber; a second layer,comprising a waterproof, breathable, stretchable membrane laminated tosaid first layer; and a third layer comprising a mesh fabric protectivelining attached to the side of said second fabric opposite the side towhich the first fabric is laminated.
 2. The fabric of claim 1 whereinsaid polypropylene filaments of said first layer are continuous.
 3. Thefabric of claim 1 wherein said polypropylene filaments of said firstlayer are of a denier no greater than
 100. 4. The fabric of claim 1,wherein said elastomeric fiber is a spandex fiber.
 5. The fabric ofclaim 1, wherein said first layer has a thermal conductivity no greaterthan 6 times that of air.
 6. The fabric of claim 1, wherein said firstlayer is abrasion resistant.
 7. The fabric of claim 1, wherein saidfirst layer has a strength of between 4.8 and 7.0 grams per denier. 8.The fabric of claim 1, wherein said first layer has a specific gravityless than that of water.
 9. The fabric of claim 1, wherein said firstlayer is generally resistant to mold, mildew and bacteria.
 10. Thefabric of claim 1, wherein said first layer is generally resistant tostains and colors.
 11. The fabric of claim 1, wherein said first layeris generally colorfast and sunfast.
 12. The fabric of claim 1, whereinsaid first layer is generally resistant to pilling.
 13. The layeredfabric of claim 18, said third layer comprising a tricot mesh material.